Numerous risk factors have been identified which are associated with drug use onset at a young age. Most of the research has focused on environmental factors, such as family, peers, neighborhood, school, and dwelling conditions. Although there has been less research conducted on characterizing the individual factors intrinsic to the liability to drug use and abuse, a variety of cognitive, motivational and affective risk characteristics have been also revealed. The features encompassing the individual liability can be parsimoniously characterized as a deficiency in behavioral regulation. Commonly reported risk factors include, for example, impulsivity, sensation seeking, emotional susceptibility, attentional deficits, difficult temperament, reactive aggressivity, behavioral deviancy, hyperactivity, low covert language capacity, and irritability. To date, however, there has been no effort to conceptualize and characterize the individual liability to substance abuse within a theoretically coherent and empirically integrated framework that encompasses these latter, and related characteristics. This level Il RSDA has three aims: The first objective is to develop and psychometrically validate a Behavior Regulation Scale (BRS) which can be used as a self-report for youth as well as an informant report by parents and by teachers. A multi-dimensional scale consisting of three traits (cognition, motivation, affect) will be developed. It is hypothesized that these traits comprise three first-order factors and one second-order factor. The second aim is to determine the extent to which the BRS scales and total score differentiated prepubertal male and female subjects who are at high risk for substance abuse (based on family history) from those at average risk. It is hypothesized that the high risk group will show greater dysregulation with males scoring higher on the motivational dimension and females scoring higher on the affective dimension. The third aim is to determine the extent to which behavioral dysregulation measured at ages 10-12 and again at 12-14 years of age, mediates family and peer risk factors on substance use and expectancies at age 12-14. It is hypothesized that behavioral dysregulation is an integral factor mediating key environmental risk factors.